Home computers have spread like wildfire since the last decade. In order to facilitate user operation of the keyboard, save desktop space, and take into account ergonomics to prevent wrist, neck and back injuries resulting from maintaining the same posture over a prolonged period, brackets have been developed and used to support the keyboard and make step-less adjustment to suit user's posture and hand positions.
Reference of keyboard bracket can be found in U.S. Pat. Nos. 4,616,798, 5,257,767, 5,924,664, and U.S. patent application Ser. No. 10/609,558 submitted by Applicant. All those patents still have drawbacks in terms of user operation angle, notably:
The screen generally is mounted on a near left side or right side of the desktop rather than in front of the user. When the user is operating the keyboard bracket, he/she has to look at the screen in a biased manner. It tends to strain and fatigue the eyes and affect user's vision. Although the cited patent references mentioned above have a rotary tray between the bracket and the desktop, the perimeter area of the swivel angle is based on the radius of the entire keyboard bracket, namely the swivel area takes a relatively large space. The space under the desktop and beside the bracket needs to be free to move. This is a big problem for people working in the office who often have limited space. Moreover, most users have cabinets located under the desktop, and the space behind the chair is always limited. It is difficult to allocate adequate space for the swivel of the keyboard bracket. Hence, most keyboard brackets are used to adjust the elevation. The swivel function to turn the screen angularly to the left and right side is not frequently used. Thus, the benefit of the keyboard bracket is not fully enjoyed.